This application is based on Patent Application No. HEI 10-351269 filed in Japan, the content of which is hereby incorporated by reference.
1. Field of the Invention
The present invention relates to a display device and an optical device provided with same.
2. Description of the Related Art
Conventionally, in singles lens reflex cameras for example, viewable within a finder are a wide focus frame 7 arranged on the interior side of a field-of-view frame 4, a spot focus frame 8, a spot photometry frame 9, and in-finder display areas 6a or 6b arranged on the exterior side of the field-of-view frame 4, as shown in FIGS. 12 and 13. The field-of-view frame 4 represents the photographic range of an image projected on the film. The wide focus frame 7 represents an autofocus (AF) area frame when a wide range photographic subject is focus detected, and the taking lens focal point is automatically adjusted. The spot focus frame 8 represents the AF area frame when a narrow range photographic subject is focus detected, and the taking lens focal point is automatically adjusted. The spot photometry frame 9 represents the photometry region for photometry of a narrow range photographic subject. The in-finder display areas 6a and 6b display photographic information such as shutter speed, aperture value, focusing condition, and photographic mode.
Among these displays, the wide focus frame 7 arranged on the interior side of a field-of-view frame 4, the spot focus frame 8, and the spot photometry frame 9 are formed by layout lines, by marking-off, drawn on the focusing glass disposed at the subject image forming position, and these frames are illuminated from outside via an LED or the like since they are not themselves luminous. For this reason a special illuminator is required, and the illumination position must be adjusted when assembling the finder.
For example, as shown in FIG. 14, a single lens reflex camera has been proposed which forms a display of the frames and the like on the interior side of the field-of-view frame 4 via a transmission-type liquid crystal panel 101 arranged adjacent to the focusing plate 67, so as to view the display of the liquid crystal panel 101 using the light passing through a taking lens 65 and reflected by a quick return mirror 66. The display of the frames and the like by the liquid crystal display 101 are difficult to see when the subject luminance is low since the display itself is not luminous.
In this single lens reflex camera, the display of the field-of-view frame 4 is constructed such that the liquid crystal panel 112 for displaying text and images is illuminated by a backlight 111, and this light is guided from a prism 113 to a pentagonal roof prism 68 so as to be viewable through an eyepiece lens 69. The light from an LED 121 is guided from a mask 122, lens 124, and prism 126 to the pentagonal roof prism 68, so as to be viewable through the eyepiece 69. For this reason space is required for the arrangement of the liquid crystal panel 112 and the LED 122 and the like.
An object of the present invention is to provide a display device of simple construction which allows a display within the device to be easily viewed, and an optical device provided with the same.
One aspect of the present invention to achieve these objects provides a display device having the construction described below, and an optical device provided with the same.
The display device and the optical device are provided with a display area achieving a display via luminance from a luminescent element. The luminescent element is provided with electrodes, and a thin film of, for example, organic electroluminescent material interposed between the electrodes, such that the thin film luminesces when a voltage is applied between the electrodes.
The electrodes of the luminescent element include a transparent electrode formed of a transparent material, and a non-transparent (opaque) electrode formed of non-transparent material, and a light-shield display mark within the finder is formed by the non-transparent electrode. Here, in the present application, the display mark includes characters, symbols, pictographs illustrations and so on.
According to this construction, a luminescent display mark is formed by the organic luminescent element, and the light-shield display mark is formed by the same organic luminescent element by rendering part of the electrode non-transparent.
The layout of a conventional device becomes unnecessary by constructing the organic luminescent element on a single substrate, and forming the non-transparent electrode by patterning same as display marks such as the frames, characters and the like desired for display. The luminescent display mark can be made easily visible by a bright display even when the periphery is dark.
Accordingly, the display mark within the device can be easily seen via a simple construction.
The organic electroluminescent material is disposed on the eyepiece side adjacent to the non-transparent electrode forming the light-shield display mark, the transparent electrode is arranged on the eyepiece side adjacent to the organic electroluminescent material, and as a result the luminescent display mark is overlaid on the light-shield display mark on the eyepiece side.
According to this construction, when the object is dark and the light-shield display mark displayed within the device is difficult to see, visibility can be improved by emitting light from the luminescent display mark overlaying the light-shield display mark.
An object brightness detector for detecting the brightness of an object to be viewed, and a luminescent display mark controller for generating luminescence of the luminescent display mark in accordance with the brightness of the object detected by the object brightness detector are both provided.
According to this construction, visibility and operating characteristics are improved by detecting the dark periphery and automatically luminescing the luminescent display mark.
The display device is provided with two or more luminescent display marks capable of luminescing independently, and a luminescent display selector for selecting the luminescent display mark. A luminescent display mark selected by the luminescent display selector is caused to luminesce.
According to this construction, a selected region or mode can be easily recognized via the lighted luminescent display mark by the selective luminescence of an optional luminescent display, i.e., lighting of the display mark, from among a plurality of luminescent display marks for displaying focus detection area, photometry area, photographic mode and the like.
Another aspect of the present invention is to provide a display device and an optical device of the following construction.
The display device and the optical device are provided with a display area achieving a display via luminance from a luminescent element. The luminescent element is provided with electrodes, and a thin film of, such as, organic electroluminescent material interposed between the electrodes, such that the thin film luminesces when a voltage is applied between the electrodes.
The luminescent element is arranged in a position through which passes light from the object to be viewed. The luminescent display mark is formed at the area through which passes the light from the object. The electrodes of the organic luminescent element are formed by a transparent material at the area through which pass the light from the object.
In this construction, a luminescent display mark can be disposed in an optical path within the device using a transparent electrode to light the luminescent element, thereby minimizing the space required, rendering the device more compact and simplifying construction compared to conventional methods which render a display from outside the optical system. Furthermore, the luminescent display area provides a readily visible and bright display even when the object is dark.
Accordingly, the display within the device is easily viewed via a simple construction.
An example of the construction of the optical device follows below.
Firstly, the optical device is described as a camera having a finder provided with an optical system for forming an object image through a taking lens. The luminescent element is disposed near the image forming position of the object image viewed through the finder.
According to this construction, when a taking lens, reflective mirror, focusing plate, pentagonal roof prism or reflective optical system, and an eyepiece lens are provided as in the case of, for example, a conventional single lens reflex camera, the luminescent element is disposed medially to the pentagonal roof prism or reflective optical system and the focusing plate for forming an object image passing through the taking lens, such that the display via the luminescent element is visible together with the formed object image.
Secondly, the optical device is described as a camera having a finder provided with an objective prism and an eyepiece prism arranged medially to an objective lens and an eyepiece lens for forming an object image between the objective prism and the eyepiece prism. The luminescent element is disposed medially to the objective prism and the eyepiece prism.
According to this construction, a display via the luminescent element together with the formed object image are both visible from the finder by disposing the luminescent element medially to the eyepiece prism and the objective prism for forming the object image.
Still another aspect of the present invention is to provide a display device and an optical device of the following construction.
The display device and the optical device are provided with a display area achieving a display via luminance from an luminescent element. The luminescent element is provided with electrodes, and a thin film of, e.g., organic electroluminescent material interposed between the electrodes, such that the thin film luminesces when a voltage is applied between the electrodes.
A plurality of display areas are integratedly formed on the same substrate, and respectively arranged on the interior side and the exterior side of the field-of-view frame within the device.
According to this construction, the device is made more compact and inexpensive by integratedly forming the luminescent display areas on the interior side and the exterior side of the field-of-view frame. Furthermore, the luminescent display marks provide readily visible and bright display even when the object is dark.
Accordingly, the display within the device is easily viewed via a simple construction.
The luminescent element is arranged in a position through which passes light from the object to be viewed. Among the electrodes of the luminescent element, the part disposed on the-interior side of the field-of-view frame within the finder is formed by a transparent material, and the part disposed on the exterior side of the field-of-view frame is formed of a non-transparent material.
According to this construction, the overall wiring resistance can be reduced and the luminance efficiency improved by using a transparent material for the part of the electrode which must be transparent so as to not hinder the field of view due to its disposition within the field-of-view frame, and using a non-transparent material which has a lower electrical resistance than the transparent material for the part of the electrode that need not be transparent on the exterior side of the field-of-view frame.
The organic luminescent element is rectangular in shape having a long edge and a short edge, wherein the extending part of the electrode is disposed on the long edge side.
According to this construction, the total wiring length of the electrodes can be reduced so as to reduce the electrical resistance and improve luminescence efficiency by arranging the extending part of the electrode, which supplies power to the electrode from an external source, on the exterior long edge of the organic luminescent element.